Abstract: Disclosed herein, the invention pertains to methods and compositions that find use in diagnostic, prognostic and characterization of neoplasia samples based on the ability of a neoplasia sample to cleave a MTS molecule of the present invention. In some embodiments, a MTS molecule disclosed herein has the formula (A-X-B-C), wherein A is a peptide with a sequence comprising 5 to 9 consecutive acidic amino acids, wherein the amino acids are selected from: aspartates and glutamates; B is a peptide with a sequence comprising 5 to 20 consecutive basic amino acids; X is a linker; and C is a detectable moiety.

Abstract: The present invention provides miniSOG proteins, polynucleotides, and methods of use. When expressed in a bacterial or mammalian cell, miniSOG proteins spontaneously incorporate flavin mononucleotide and produce fluorescence and singlet oxygen upon excitation. Uses include optical and electron microscope imaging, in vivo imaging, detection and localization of protein-protein interactions, and photoablation.

Abstract: Disclosed herein, the invention pertains to methods and compositions that find use in treatment, diagnosis, prognosis and characterization of disease and disease samples based on the ability of a disease sample to cleave a MTS molecule of the present invention. The MTS molecules of the present invention have a formula as disclosed herein and wherein A is a peptide with a sequence comprising 5 to 9 consecutive acidic amino acids, wherein the amino acids are selected from: aspartates and glutamates; B is a peptide with a sequence comprising 5 to 20 consecutive basic amino acids; X and Y are linkers; P is a pre-targeting moiety; M is a macromolecular carrier, C is a detectable moiety; and T is a compound for delivery to a target, including for example a therapeutic compound.

Abstract: The disclosure provides method and compositions for visualizing protein turnover. In particular, the disclosure provides methods and compositions useful for measuring the age of particular proteins or the dynamics of localized protein translation.

Abstract: Methods using somatic hypermutation (SHM) for producing polypeptide and nucleic acid variants, and nucleic acids encoding such polypeptide variants are disclosed. Such variants may have desired properties. Also disclosed are novel polypeptides, such as improved fluorescent proteins, produced by the novel methods, and nucleic acids, vectors, and host cells comprising such vectors.

Abstract: Imaging systems for fluorescence guided surgery are provided. An imaging system comprises a light source unit for providing one or more illumination and excitation lights to a target, a detection unit for detecting reflectance and fluorescence from the target, an optical train for directing the one or more illumination and excitation lights from the light source unit to the target and for directing the reflectance and fluorescence from the target to the detection unit, and a control unit for controlling the light source unit and the detection unit. Imaging methods for fluorescence guided surgery are also provided.

Abstract: The invention provides engineered red-shifted channelrhodopsin variants. In some embodiments, the channelrhodopsin variants are characterized by improved membrane trafficking, expression, and/or unique spectral and kinetic properties.

Abstract: Compounds and methods for determining transmembrane potential, monitoring changes in transmembrane potential, and/or drug screening are provided. In one aspect, compounds of the invention have a structure according to the formula: E-M-A, wherein A is a fluorophore, selected from xanthenes, eoumarins, cyanines, bimanes, and difluoroboradizaindacenes, charged at physiological pH; M is a molecular wire; and E is a hydrophobic moiety, wherein A and E are capable of being involved in a photo-induced, intramolecular electron transfer that quenches the fluorescence of A in response to a voltage condition. When in use, compounds of the invention are membrane-impermeant and oriented within the cell membrane such that the charged moiety localizes at the outer leaflet of the lipid bilayer and the hydrophobic moiety and molecular wire associate with the hydrophobic portion of the lipid bilayer.

Abstract: The present invention provides methods for guiding preservation of neurons or nerves during surgery by administering a fluorescently-labeled peptide or aptamer that specifically binds to the neurons or nerves. The invention further provides targeting molecules of fluorescently-labeled peptides or aptamers that specifically bind to neurons or nerves and for compositions thereof.

Abstract: This invention provides tandem fluorescent protein construct including a donor fluorescent protein moiety, an acceptor fluorescent protein moiety and a linker moiety that couples the donor and acceptor moieties. The donor and acceptor moieties exhibit fluorescence resonance energy transfer which is eliminated upon cleavage. The constructs are useful in enzymatic assays.

Abstract: A chimeric phosphorylation indicator (CPI) as provided herein can contain a donor molecule, a phosphorylatable domain, a phosphoaminoacid binding domain (PAABD), and an acceptor molecule. Where the phosphorylatable domain is phosphorylatable by protein kinase C (PKC), the CPI is a c-kinase activity reporter (CKAR). Donor and acceptor molecules may be, independently, fluorescent proteins such as non-oligomerizing fluorescent proteins. A CPI can contain a phosphorylatable polypeptide and a fluorescent protein; the phosphorylatable polypeptide may be contained within the sequence of the fluorescent protein, or the fluorescent protein may be contained within the sequence of the phosphorylatable polypeptide. The spatiotemporal properties of the PKC signal pathway may be tested with CKAR, calcium-sensing fluorophores and FRET-based translocation assays. Polynucleotides encoding such CPIs, and kits containing the indicators and/or the polynucleotides, are provided.

Abstract: A generic structure for the peptides of the present invention includes A-X-B-C, where C is a cargo moiety, the B portion includes basic amino acids, X is a cleavable linker sequence, and the A portion includes acidic amino acids. The intact structure is not significantly taken up by cells; however, upon extracellular cleavage of X, the B-C portion is taken up, delivering the cargo to targeted cells. Cargo may be, for example, a contrast agent for diagnostic imaging, a chemotherapeutic drug, or a radiation-sensitizer for therapy. Cleavage of X allows separation of A from B, unmasking the normal ability of the basic amino acids in B to drag cargo C into cells near the cleavage event. X is cleaved extracellularly, preferably under physiological conditions. D-amino acids are preferred for the A and B portions, to minimize immunogenicity and nonspecific cleavage by background peptidases or proteases.

Abstract: The present invention provides miniSOG proteins, polynucleotides, and methods of use. When expressed in a bacterial or mammalian cell, miniSOG proteins spontaneously incorporate flavin mononucleotide and produce fluorescence and singlet oxygen upon excitation. Uses include optical and electron microscope imaging, in vivo imaging, detection and localization of protein-protein interactions, and photoablation.

Abstract: The invention provides compositions useful as molecular probes. In particular, the invention provides activatable cell penetrating peptides comprising a fluorescence donor and a fluorescence acceptor. Exemplary fluorescence donors and fluorescence acceptors include compounds derived from cyanine. Also provided are ratiometric, multispectral, and excitation lifetime imaging methods for detecting the molecular probes provided herein.

Abstract: The invention provides engineered red-shifted channelrhodopsin variants. In some embodiments, the channelrhodopsin variants are characterized by improved membrane trafficking, expression, and/or unique spectral and kinetic properties.

Abstract: The present invention provides a method for reducing undesirable light emission from a sample using at least one photon producing agent and at least one photon reducing agent (e.g. dye-based photon reducing agents). The present invention further provides a method for reducing undesirable light emission from a sample (e.g., a biochemical or cellular sample) with at least one photon producing agent and at least one collisional quencher. The present invention also provides a method for reducing undesirable light emission from a sample (e.g., a biochemical or cellular sample) with at least one photon producing agent and at least one quencher, such as an electronic quencher. The present invention also provides a system and method of screening test chemicals in fluorescent assays using photon reducing agents. The present invention also provides compositions, pharmaceutical compositions, and kits for practicing these methods.

Abstract: A generic structure for the peptides of the present invention includes A-X-B-C, where C is a cargo moiety, the B portion includes basic amino acids, X is a cleavable linker sequence, and the A portion includes acidic amino acids. The intact structure is not significantly taken up by cells; however, upon extracellular cleavage of X, the B-C portion is taken up, delivering the cargo to targeted cells. Cargo may be, for example, a contrast agent for diagnostic imaging, a chemotherapeutic drug, or a radiation-sensitizer for therapy. Cleavage of X allows separation of A from B, unmasking the normal ability of the basic amino acids in B to drag cargo C into cells near the cleavage event. X is cleaved extracellularly, preferably under physiological conditions. D-amino acids are preferred for the A and B portions, to minimize immunogenicity and nonspecific cleavage by background peptidases or proteases.

Abstract: The present invention provides methods for guiding preservation of neurons or nerves during surgery by administering a fluorescently-labeled peptide or aptamer that specifically binds to the neurons or nerves. The invention further provides targeting molecules of fluorescently-labeled peptides or aptamers that specifically bind to neurons or nerves and for compositions thereof.

Abstract: A generic structure for the peptides of the present invention includes A-X-B-C, where C is a cargo moiety, the B portion includes basic amino acids, X is a cleavable linker sequence, and the A portion includes acidic amino acids. The intact structure is not significantly taken up by cells; however, upon extracellular cleavage of X, the B-C portion is taken up, delivering the cargo to targeted cells. Cargo may be, for example, a contrast agent for diagnostic imaging, a chemotherapeutic drug, or a radiation-sensitizer for therapy. Cleavage of X allows separation of A from B, unmasking the normal ability of the basic amino acids in B to drag cargo C into cells near the cleavage event. X is cleaved extracellularly, preferably under physiological conditions. D-amino acids are preferred for the A and B portions, to minimize immunogenicity and nonspecific cleavage by background peptidases or proteases.

Abstract: A generic structure for the peptides of the present invention includes A-X-B-C, where C is a cargo moiety, the B portion includes basic amino acids, X is a cleavable linker sequence, and the A portion includes acidic amino acids. The intact structure is not significantly taken up by cells; however, upon extracellular cleavage of X, the B-C portion is taken up, delivering the cargo to targeted cells. Cargo may be, for example, a contrast agent for diagnostic imaging, a chemotherapeutic drug, or a radiation-sensitizer for therapy. X may be cleaved extracellularly or intracellularly. The molecules of the present invention may be linear, cyclic, branched, or have a mixed structure.